Optical instrument.



W. WORK. OPTICAL INSTRUMENT. APPLICATION FILED AUG. 13, 1913.

. 1 088 501 Patented Feb. 24, 19 14.

INVENTOI? ,lj- WzZham V0170 I rl ATTORNEYS coLL'MBIA PLANOGRAPMCOHWASHINGTQN. D. c-.

'rniv WILLIAM WORK, OF BROCKTON', MASSACHUSETTS,

BSSIGNOE OF ONE-HALF '10 HERMAN S. HEWETT, OF BROCK'ION, MASSACHUSETTS.

OPTICAL INSTRUMENT.

osasov.

Application filed August 13, 1913.

I! '0 all whom it may concern Be it known that I, YVILLIAM 011K, asubject of the King of Great Britain, and a resident of Brockton, in thecounty of Plymouth and State of Massachusetts, have invented a new andImproved Optical Instrument, of which the following is a full, clear,and exact description.

The object of the invention is to provide a new and improved opticalinstrument to be used in conjunction with a plano-retinoscope, andarranged to permit of quickly and accurately determining the amount ofrefraction of the eve of a patient under observation by an oculist orother examiner, to insure fitting the patient with eyeglasses orspectacles having correct spherical, oylindrical or compound lenses.

in order to accomplish the desired result use is made of an indicatorand movable actuating means connected with the said indicator andcontrolled by the examiner during the use of the plano-retinoscope.

A practical embodiment of the invention is represented in theaccompanying drawings forming a partof this specification, in whichsimilar characters of reference indi 'ate corresponding parts in all theviews.

Figure l is a side elevation of the optical instrument as applied; Fig.2 is an enlarged side elevation of part of the instrument with the coverof the casing removed; Figs. 3 and 3 are sectional plan views of thesame; Fig. 4; is a cross section of the same; Fig. 5 is a frontelevation of the instrument with the adjusting means for the stand shownin section; Fig. (5 is a perspective view of the head frame for theexaminer; and Fig. 7 is an enlarged sectional side elevation of theadjusting and locking device for the hori zontal tubular arm of thestand.

The improved optical instrument is mounted on a suitably constructedstand A provided on its top with a horizontal tubular arm B sup 'iortingat its forward end a casing C in which is journaled thetransversely-extending shaft D of an indicating wheel D, provided on itsperipheral face with numerals indicating diopt-ers. The diopter numeralsare adapted to be succes sively read through an opening C arranged inthe front of the casing C on rotating the wheel D, as hereinafter morefully explained. On the shaft D of the indicating S eoification ofLetters Patent.

.f-atented Feb. 2d, 191.4.

Serial No. 784,547.

wheel D is secured a gear wheel E in mesh with a pinion 4E secured onthe transversely-extending shaft F of a drum F arranged within thecasing C. On the drum ii winds and unwindsa cord G extending through anopening in the front of the casmg C and having its outer end providedwith a ring G adapted to be engaged with a rod H forming part of a headframe H adapted to be attached to the head of the oculist or otherexaminer. The lower end of the rod H is provided with a bridge 11adapted to be seated on the nose of the examiner, and the rod H is alsoprovided with temples H adapt-ed to engage the ears of the examiner tosecurely hold the head frame H in position on the examiners head. Thering G is engaged with the rod H higher up or farther down to hold thecord in an approximately horizontal position when the device is in use.A second cord I winds and unwinds on the hub D of the indicating wheelD, and the said cord I extends rearwardly through the casing G into thetubular arm B, and the rear end of the said cord 1 is attached to oneend of a spring J secured at its rear end to a plug K held in the rearend of the tubular arm B.

The cords G and I are so arranged that when the examiner moves his head,with the frame H attached thereto, awav from the casing C then the cordG unwinds from the drum F which is thereby rotated so as to rotate theindicating wheel D which in turn winds up the cord I against the tensionof its spring J. "When the examiner moves his head toward the using Cthe wheel D is turned in the reverse direction by the action of thespring-pressed cord I whereby the cord G is wound up on the drum nowrotated from the wheel D.

On the casing G is secured a depending head rest L adapted to abutagainst the forehead of the patient to be examined, as will be readilyunderstood by reference to Fig. 1.

The stand A. is preferably provided with an extension telescopingsection A controlled by a raising and lowering device N in the form of arack and pinion, to allow of raising or lowering the head rest L to suitthe height of the patient to be examined.

The tubular arm B is preferably provided with a depending shank Bfitting into the extension section A of the stand, and the sa1d shank Bis provided with a vertical groove engaged by a sprmgpressed pin 0mounted on the section A to hold the arm B against lateral movement.

In using the instrument the patient is equipped with the ordinary trialframe, and the examiner is provided with a piano-retinoscope to enablehim to examine the patients eye relative to any defect in retraction(see Fig. l). The patient is preferably seated on a chair in front ofthe stand A with the forehead abutting against the head rest L. Theframe H is attached to the examiners head, as previously mentioned, andthe examiner now moves his head toward or from the patient until heobserves that the shadow has no movement in any one direction. It willbe noticed that when the examiner moves his head away from that of thepatient the cord G is drawn out to rotate the drum F and the wheel D,and when the examiner moves the head toward the patient the wheel D isrotated in the reverse direction by the action of the spring-pressedcord 1, and the cord G is unwound from the drum F as the latter isrotated from the wheel D. Now as soon as the examiner has determined thedefect of refraction of the patients eye as above mentioned he can readat a glance the corresponding diopter nu- V meral appearing in theopening C.

In case the defect requires a plus lens or a weaker or stronger minuslens than the range of the instrument 1.00 to -3.50, a lens may be putinto the trial frame worn by the patient so as to bring the defectwithin range of the instrument. When the in strument is in use and theforehead of the patient rests on the head rest L then the eye of thepatient is approximately in vertical alinement with the opening in theeasing 0 through which the cord G passes. The cord G is of such a lengththat when the retinoscope held by the examiner is one meter from the eyeof the patient the dioptric numeral 1.00 on the indicating wheel D willshow through the opening C in the casing C; when the retinoscope is halfa meter from the eye of the patient 2.00 will show in the opening 0, andso on in pro portion with all the other numerals on the wheel D. Nowwhen the examiner moves his head away from the patients head the cord Gis drawn out to cause a rotation of the drum F and the wheel D so thatthe latter displays successively the diopter numerals, and when theexaminer has determined the defective refraction of the patients eye thediopter numeral appearing in the opening G indicates the amount of suchdetective refraction of the patients eye.

The instrument shown and described has a range of between 1.00 and -3.50diopters and the desired result is obtained without requiring continuedchanging of lenses in the trial frame of the patient, as heretotorepractised.

Having thus described my invention, 1 claim as new and desire to secureby Letters Patent:

1. E n optical instrument of the class described and to be used inconjunction with a retinoscope, comprising a registering device tcrindicating diopters, and an actuating means connected with the saidregistering device for actuating the same according to the distancebetween the examiner and the patient examined by the examiner.

2. An optical instrument of the class described and to be used inconnection with a retinoscope, comprising a registering dei e torindicating diopters and provided with a drum and cord winding andunwinding on the said drum, and a frame for attachment to the examinershead and connected with the said cord to actuate the registering deviceaccording to the distance between the examiner and the patient exam inedby the examiner.

3. An optical instrument, comprising a stand provided with a head restfor the patient to be examined, an indicating wheel mounted on the saidstand, a drum mounted on the stand and geared with the said wheel, acord winding on the said drum for turning the drum and wheel in onedirection on moving the cord, a spring device for turning the wheel anddrum in the opposite direction to wind up the cord, and a head frame forattachment to the examiners head and connected with the outer end of thesaid cord.

4:. An optical instrument, comprising a stand provided with a head restfor the person to be examined, an indicating wheel mounted on the saidstand, a drum mounted on the stand and geared with the said wheel, acord winding on the said drum for turning the drum and wheel in onedirection on unwinding the cord, a spring device for turning the wheeland drum in the opposite direction to wind up the cord, and a head framehaving a rod terminating in a nose bridge and secured to the said cordand having temples for engagement with the ears of the examiner.

5. An optical instrument to be used in conjunction with a retinoscope,comprising a stand provided with a horizontal tubular arm carrying acasing at its forward end, the casing having an opening, an indicatingwheel journaled in the casing and provided at its peripheral face withnumerals indicating diopters and adapted to appear in the said casingopening on rotating the wheel, a drum journaled in the casing, a gearingconnecting the drum with the said wheel, a cord winding on the saiddrum, a head frame for attachment to the examiners head and connectedwith the outer end of the said cord to turn the drum and wheel in aforward direction, and a spring device connected with the said wheel toturn the latter and the drum in a return direction.

6. An optical instrument to be used in conjunction with a retinoscope,comprising a stand provided with a horizontal tubular arm carrying acasing at its forward end, the casing having an opening, an indicatingwheel journaled in the casing and provided at its peripheral face withnumerals indieating diopters adapted to appear in the said casingopening on rotating the wheel, a drum journaled in the casing, a gearingconnecting the drum with the said wheel,

a cord winding on the said drum, :1 head frame for attachment to theexaminers head and connected with the outer end of the said cord to turnthe drum and wheel in a forward direction, a second cord winding on thehub of the said wheel and extending within the said tubular arm, and aspring connected with the said second cord and the rear end of the saidarm.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

l/VILLIAM WVORK. Witnesses GEORGE E. FISHER, FLORENCE M. KEENE.

Copies 0! this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

